prstream.java

iText是一个能够快速产生PDF文件的java类库。iText的java类对于那些要产生包含文本

/*
 * $Id: PRStream.java 2446 2006-11-08 17:33:44Z psoares33 $
 * $Name$
 *
 * Copyright 2001, 2002 by Paulo Soares.
 *
 * The contents of this file are subject to the Mozilla Public License Version 1.1
 * (the "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the License.
 *
 * The Original Code is 'iText, a free JAVA-PDF library'.
 *
 * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
 * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
 * All Rights Reserved.
 * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
 * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
 *
 * Contributor(s): all the names of the contributors are added in the source code
 * where applicable.
 *
 * Alternatively, the contents of this file may be used under the terms of the
 * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
 * provisions of LGPL are applicable instead of those above.  If you wish to
 * allow use of your version of this file only under the terms of the LGPL
 * License and not to allow others to use your version of this file under
 * the MPL, indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by the LGPL.
 * If you do not delete the provisions above, a recipient may use your version
 * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the MPL as stated above or under the terms of the GNU
 * Library General Public License as published by the Free Software Foundation;
 * either version 2 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
 * details.
 *
 * If you didn't download this code from the following link, you should check if
 * you aren't using an obsolete version:
 * http://www.lowagie.com/iText/
 */

package com.lowagie.text.pdf;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.zip.DeflaterOutputStream;

import com.lowagie.text.Document;
import com.lowagie.text.ExceptionConverter;

public class PRStream extends PdfStream {
    
    protected PdfReader reader;
    protected int offset;
    protected int length;
    
    //added by ujihara for decryption
    protected int objNum = 0;
    protected int objGen = 0;
    
    public PRStream(PRStream stream, PdfDictionary newDic) {
        reader = stream.reader;
        offset = stream.offset;
        length = stream.length;
        compressed = stream.compressed;
        streamBytes = stream.streamBytes;
        bytes = stream.bytes;
        objNum = stream.objNum;
        objGen = stream.objGen;
        if (newDic != null)
            putAll(newDic);
        else
            hashMap.putAll(stream.hashMap);
    }

    public PRStream(PRStream stream, PdfDictionary newDic, PdfReader reader) {
        this(stream, newDic);
        this.reader = reader;
    }

    public PRStream(PdfReader reader, int offset) {
        this.reader = reader;
        this.offset = offset;
    }
    
    public PRStream(PdfReader reader, byte conts[]) {
        this.reader = reader;
        this.offset = -1;
        if (Document.compress) {
            try {
                ByteArrayOutputStream stream = new ByteArrayOutputStream();
                DeflaterOutputStream zip = new DeflaterOutputStream(stream);
                zip.write(conts);
                zip.close();
                bytes = stream.toByteArray();
            }
            catch (IOException ioe) {
                throw new ExceptionConverter(ioe);
            }
            put(PdfName.FILTER, PdfName.FLATEDECODE);
        }
        else
            bytes = conts;
        setLength(bytes.length);
    }
    
    /**Sets the data associated with the stream
     * @param data raw data, decrypted and uncompressed.
     */
    public void setData(byte[] data) {
        remove(PdfName.FILTER);
        this.offset = -1;
        if (Document.compress) {
            try {
                ByteArrayOutputStream stream = new ByteArrayOutputStream();
                DeflaterOutputStream zip = new DeflaterOutputStream(stream);
                zip.write(data);
                zip.close();
                bytes = stream.toByteArray();
            }
            catch (IOException ioe) {
                throw new ExceptionConverter(ioe);
            }
            put(PdfName.FILTER, PdfName.FLATEDECODE);
        }
        else
            bytes = data;
        setLength(bytes.length);
    }

    public void setLength(int length) {
        this.length = length;
        put(PdfName.LENGTH, new PdfNumber(length));
    }
    
    public int getOffset() {
        return offset;
    }
    
    public int getLength() {
        return length;
    }
    
    public PdfReader getReader() {
        return reader;
    }
    
    public byte[] getBytes() {
        return bytes;
    }
    
    public void setObjNum(int objNum, int objGen) {
        this.objNum = objNum;
        this.objGen = objGen;
    }
    
    int getObjNum() {
        return objNum;
    }
    
    int getObjGen() {
        return objGen;
    }
    
    public void toPdf(PdfWriter writer, OutputStream os) throws IOException {
        byte[] b = PdfReader.getStreamBytesRaw(this);
        PdfEncryption crypto = null;
        if (writer != null)
            crypto = writer.getEncryption();
        PdfObject objLen = get(PdfName.LENGTH);
        int nn = b.length;
        if (crypto != null)
            nn = crypto.calculateStreamSize(nn);
        put(PdfName.LENGTH, new PdfNumber(nn));
        superToPdf(writer, os);
        put(PdfName.LENGTH, objLen);
        os.write(STARTSTREAM);
        if (length > 0) {
            if (crypto != null)
                b = crypto.encryptByteArray(b);
            os.write(b);
        }
        os.write(ENDSTREAM);
    }
}